As more and more electronic apparatuses of different dimensions, functions, and manufacturers prevail in modern information society, they demand standardized connection mechanism to interconnect with each other for interaction and/or cooperation. One of the most used connection standards is USB (Universal Serial Bus) standard defined by USB specification, which is developed and maintained by USB Implementers Forum, Inc.
A connection standard is implemented by mechanical connector and electrical signaling. Mechanical connector defines dimensions of plugs and receptacles. Electrical signaling defines general interconnect scheme, e.g., the manner in which devices (peripheral apparatuses) connect to and communicate with host (a central apparatus), including topology of interconnection (e.g., star topology and/or daisy chain), involved communication layers, relationship and interaction between the communication layers for accomplishing information exchange, as well as roles of interconnect participants (e.g., host, hub and/or device).
For example, regarding mechanical connector, USB 3.0 specification defines the following connectors: USB 3.0 standard-A plug and receptacle, USB 3.0 standard-B plug and receptacle, USB 3.0 powered-B plug and receptacle, USB 3.0 micro-B plug and receptacle, USB 3.0 micro-A plug and USB 3.0 micro-AB receptacle, etc. Regarding electrical signaling, USB 3.0 (and 3.1) specification defines SuperSpeed interconnect besides low-speed, full-speed and high-speed interconnects of USB 2.x specification. The USB SuperSpeed interconnect architecture includes communication layers like physical layer, link layer and protocol layer; mechanism for robustness and power management; participants such as peripheral devices, hubs and hosts; and data flow model.
While standardized mechanical connector facilitates product design and lowers manufacturing cost and effort for different electronic apparatuses, electrical signaling of the same standard can hardly satisfy various demands of different electronic apparatuses. For example, the 5.0 GHz frequency of USB SuperSpeed interconnect can cause EMI (Electromagnetic Interference) to degrade functionalities which rely on wireless connection.